The present invention relates to a display device, for example, a liquid crystal display device.
A typical liquid crystal display device is configured such that, on one surface of a substrate thereof, a plurality of signal lines are juxtaposed in the longitudinal direction as well as in the lateral direction, and respective pixels are driven in response to signals supplied to these signal lines. The respective pixels are arranged in a matrix array, and a liquid crystal display part is constituted by these pixels. Liquid crystal is sandwiched between one substrate and another substrate such that the liquid crystal is disposed at positions which correspond to the pixels.
The signal lines extend to regions outside the liquid crystal display part and are provided with terminals at the extended ends thereof. These terminals are made to face down, and they constitute portions which are connected with bumps of a semiconductor device on which the liquid crystal display part is mounted. The signals are supplied to the signal lines from the semiconductor device.
Here, in a typical case, the signal lines are covered with an insulation film inside of a region of the liquid crystal display part, and the insulation film is formed such that it extends to the outside of the liquid crystal display part. Accordingly, the terminals are formed by exposing portions of the signal lines by forming holes in the insulation film and by stacking, for example, conductive layers, which exhibit the strong resistance against electrolytic corrosion, on these exposed portions.
Further, even inside of the liquid crystal display part, conductive layers are provided so as to be arranged as separated layers; and, when these conductive layers are to be connected with each other, an operation is carried out to form holes (through holes) in an insulation film which is formed between the conductive layers. In this case, the formation of the above-mentioned holes (through holes) in the terminal parts is usually performed simultaneously. Such simultaneous hole forming operations are performed with a view toward achieving a reduction in the manufacturing man-hours.
Further, as the insulation film, there is a known insulation film which is formed of a sequentially stacked film, which is constituted of an inorganic material layer and an organic material layer, for reducing the capacitance at a portion where the conductive film, which constitutes a layer below the insulation is film, and the conductive film, which constitutes a layer above the insulation film, are overlapped relative to each other (for example, see JP-A-2000-171817).